Folding closure assemblies for closing and opening are well known. The folding assemblies may be solid panels, or alternatively, may be an open grill design. Such assemblies are used across store fronts in shopping malls and the like. When the closure is closed to fill the opening, the panels are substantially in line and flat, and when the closure is open, the panels are accordioned together and in some cases may fit into a compartment at one side of the opening. The use of the term "panels" throughout the specification refers to panels made of solid or one piece sheets, transparent sheets with supporting strips, or grills with apertures between supporting strips.
Folding closure assemblies are generally supported by rollers running in a track extending across the top of the opening. A bottom track is not generally used as it is preferred to have a smooth floor without obstructions in the opening, particularly for shopping malls.
There are many different designs of folding closure assemblies for store fronts and the like. Most of these designs are lightweight, generally made from aluminum, but strong enough to prevent access. Some have clear panels of glass or plastic therein, others are grill like which reduces the weight still further. Most of the designs have vertical hinges at the edges of each panel extending from the top to the bottom. The full length hinge tends to require some force to open and close due to friction, and the force to open one hinge must be multiplied by the number of hinges in the closure. Thus the overall force to open and close the assembly can be more than one individual can apply. Another disadvantage with some existing designs of folding closures is that they have many different components which increases the cost, makes the design complicated and the assembly heavy.
The U.S. Pat. No. 4,660,613 issued on Apr. 28, 1987 discloses an improved folding closure which overcomes many of the above-discussed problems by providing a novel hinge construction for pivotally joining adjacent panels of the closure, which is considerably easier to assemble. More particularly, the hinge construction includes an integral female hinge member with a pair of semi-circular grooves therein receiving curved side edges of the panels to be joined together. To assemble the hinge, it suffices to telescope the male hinge members in the female hinge member and to supply a screw for locking the components together and preventing accidental removal of the male hinge member from the female hinge member.
Although this form of hinge construction is superior to prior designs in terms of ease of assembly and operation, the manufacture of the female hinge member has been found to be complex and necessitating a comparatively high amount of raw material.